This invention relates to a switch assembly for a conveyor apparatus to prevent undesired movement of the conveyor apparatus and to regulate the slack or tension in the conveyor belt.
Conveyors are utilized in many process operations to automate and expedite the transportation and handling of materials. Typically, a conveyor includes a conveyor belt driven by some form of drive apparatus and including some form of tension take up loop or slack loop permitting the installation and adjustment of the conveyor belt.
It is not uncommon for a mechanical difficulty with the conveyor apparatus to stop movement of the conveyor belt or in making the belt slack or tensioned. In such a situation it is desirable to momentarily or completely cease operation of the conveyor apparatus until the problem is rectified. Also, conveyor belts are naturally slightly displaced upon the addition or removal of weight to the system as well as by insignificant blocking such as is caused by poor lubrication or insignificant material blockage. However, a simple and effective device to sense and the operation of a conveyor apparatus which accommodates slight natural displacement has not been forthcoming.
Such a switch assembly would be extremely important for preventing injury to employees and materials transported on the conveyor belt. It would be desirable to provide a switch which would terminate operation of the conveyor apparatus should a limb or an article of clothing of an unfortunate person become entangled therein or upon adding or removing a burdensome load from the conveyor belt. Such a switch could provide a hands-free, fail safe safety mechanism necessary to prevent injury and material damage.
In a similar manner such a switch could prevent unnecessary damage to the conveyor apparatus and the materials being transported by terminating operation of the apparatus before excessive resistance or inappropriate operation takes its toll.
Further, it is desirable to provide a conveyor apparatus which can take up the slack in a conveyor belt on the fly. Presently available conveyor apparatus tend to have a problem with maintaining consistent movement of the conveyor belt. Such operation is very important, especially in the movement of fragile items including eggs or the like.
Since it is desirable to sense and respond to conveyor apparatus malfunctions or undesirable changes in operation and simple and efficient sensing devices are not available, it is desirable to provide a sensing device to overcome such problems. It is desirable to provide a switch assembly which will allow for a degree of movement of the conveyor belt so that the conveyor apparatus is not turned off at the slightest displacement of the conveyor belt. Further, the conveyor belt may experience deviations in either speeding up or slowing down and it is therefore desirable to provide a switch assembly capable of sensing both types of deviations.